Light and electron microscope observation of virus-induced Tetrahymena pyriformis in newborn mice (Mus musculus albinicus) brain.

Newborn mice were infected intracerebrally with abacterial cultures of the GL strain of Tetrahymena pyriformis, induced experimentally six years ago in vitro with Coxsackie B-5 virus. In the brain of the test animals there were pathologic changes similar to those found in the primary investigation of the pathogenicity of this strain, i.e., after 96 h of contact with the virus. Thus, the pathogenicity acquired by T. pyriformis, as well as the persistence of Coxsackie B-5 virus in this ciliate, can be considered stable. Despite such specific changes in the biological properties of T. pyriformis, the changes were not reflected in the morphology of the protozoon, which was investigated by means of light and electron microscopy.